Frost Dates for 74039 — Kellyville, Oklahoma

Half of springs at Bristow, OK see their last 32°F night by April 9; only one in ten is past it by March 24, and one in ten still has one after April 27. Planting tender crops after April 17 leaves a 30% risk of a frost on them, after April 22 20%, and after April 27 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 60% of the 114 Oklahoma stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 25 in half of years, as early as October 10 one year in ten, and holds off past November 8 one year in ten. A hard freeze of 28°F follows 8 days later, around November 2; in spring the one-in-ten date for 28°F is April 16, 11 days before the 32°F one. The freeze-free season lasts 196 days in a typical year, shorter than at 91% of the 114 Oklahoma stations; it reaches 216 days one year in ten and falls short of 174 one year in ten. On average 78 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 13 days longer, to about April 22, and return around October 15. Severe cold of 16°F or below comes every winter, usually between December 7 and February 23.

July is the warmest month at Bristow, OK, averaging 92°F by day and 69°F at night; January is the coldest at 49°F and 26°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 76% of years.

Warmth for growing adds up to 4,784 growing degree days a year (base 50°F), fewer than at 88% of the 114 Oklahoma stations. 38% of them (1,828) have built up by the end of June, and July adds the most, 945. Precipitation totals 42.1 inches a year, most in May (5.8") and least in January (1.4"); May to September bring 51% of it.

The nearest other station, Tulsa R L Jones Jr Airport, OK, 16 miles northeast of Kellyville and 192 feet lower, has a last frost 10 days earlier (March 30), a first frost 10 days later (November 4), a season 24 days longer.

The first measurable snow (0.1 inch or more) in Kellyville usually arrives around December 12, and the last of the season around February 3. Those are the middle dates across the winters of 1991–2020 at Bristow, OK, 11.5 miles away: half of years saw snow earlier, half later. Snow fell in 90% of those winters. The last 32°F night of spring typically comes 65 days after the last snow.

ZIP 74039 is 12 miles from Bristow, OK, which stands at 830 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 74010 (Bristow). The 2023 USDA Plant Hardiness Zone Map lists ZIP 74039 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.